Reaction apparatus



Dec. 18, 1962 Filed Nov. 18, 1958 n12 Pzofan T104107 AIR R. J. BROOKS EI'AL REACTION APPARATUS FIG 2/, ,4-0 COOLED HEAT RECIHCULRTION Eye/JAN.

M l X TURE REACTION M (X TURE E VA PORA TOR /2 5 Pearce noun TOR 2 Sheets-Sheet 1 INTERFACE CoNTQOLLER Mum RE NEUTQflL/Z E 0 PRODUCT 3 ,4 1 6 INVENTORS 50!" 8/576 7 w. fen-art Dec. 18, 1962' R. J. BROOKS ETAL 3,069,243

REACTION APPARATUS Filed NOV. 18. 1958 2 Sheets-Sheet 2 COOLED RE CIRCULATION MIXTURE United States Patent Ofifice 3,069,243 Patented Dec. 18, 1962 3,069,243 REACTION APPARATUS Richard J. Brooks and Burton Brooks, Seattle, Wash., as-

signors to The Chemithon Corporation, Seattle, Wash, a corporation of Washington Filed Nov. 18, 1958, Ser. No. 774,740 5 Claims. (Cl. 23-260) This invention relates to a sulfonation process, a sulfation process and apparatus for carrying out these processes, and more particularly, to said processes where the reactant and the active sulfonating and/or sulfating agent are substantially completely simultaneously contacted, mixed and reacted, and then subjected to conditions to remove the extraneous gas added or generated therein.

A number of processes have been employed for reacting organic materials such as an alkyl aromatic, i.e., alkyl benzene, having l0l8 carbon atoms in the side chain with a sulfonating agent to produce an alkyl benzene sulfonic acid, and an organic material like an ester with a sulfating agent. A typical batch reaction process may be carried out in a 2,500 gallon glass lined vessel equipped with a mixer. Additional mixing is also provided by an external circulation system which discharges into the top of the sulfonator through a distributor head. A heat exchanger of about 1,000 square feet is employed in the circulating system to remove the heat of sulfonation. Stainless steel (type 316) is satisfactory for the circulating system and may be used for the reactor if desired. The sulfonation cycle starts with the charging of 1,400 gallons of an alkyl benzene to the vessel. Circulation of alkyl benzene is started through the exchanger and oleum is slowly added to the alkyl benzene at the suction side of the circulating pump. The acid addition rate is controlled so that the reaction temperature does not exceed 85 F., and usually about one and one-half to two hours, are required for the acid addition. After 740 gallons of twenty-two (22%) percent oleum have been added the mixture is digested at 85 F. for one hour. With these conditions 98-99% of the alkyl benzene is converted to alkyl benzene sulfonic acid. A typical analysis of the stock at this stage shows: sulfonic acid, 60-61%; sulfuric acid, 38- 39%; water, 0.5%; and, residual oil, 0.5%.

Turning now to a batch process for separating the alkyl benzene sulfonic acid from excess sulfonating agent, it has been found that the excess sulfonating agent must be diluted with water to lower the concentration to a value of approximately eighty (80%) percent sulfuric acid so as to obtain a substantially complete separation from the sulfuric acid from the sulfonation mix. This is a result of the mutual insolubility of the sulfonic and sulfuric acids. This dilution step requires a thorough mixing of the diluted sulfonated mix in order to remove the localized gel structure formed between sulfonic acid and the water. The temperature during dilution is controlled to a value in the range of 135-145 F. maximum so as to minimize the color degradation of the alkyl benzene sulfonic acid. As is well known, if the temperature increases to above approximately 145 F., even with the decrease in the concentration of the sulfuric acid, there is further reaction between the alkyl benzene sulfonic acid and the sulfuric acid to degrade the color of the sulfonic acid. If the acid is diluted below approximately eighty (80%) percent sulfuric acid, the product does not have any higher active content of sulfonic acid but the setting time required to separate the sulphonic acid and the sulfuric acid is reduced. However, the chief disadvantagesof greater dilution are that corrosion of stainless steel equipment (sulfonator heat exchanger) is greately increased and the color quality of the product is poor. For example, laboratory tests indicate that the corrosive rate product.

of sixty (60%) percent sulfuric acid dilution is up to approximately one hundred times that of eighty percent sulfuric acid dilution.

Turning now to a specific separation of the sulfonic acid from the excess sulfonating agent for the batch process employing a 2,300 gallon batch of the alkyl benzene and the sulfuric acid, the sulfuric acid is diluted to a concentration of approximately eighty (80%) percent strength and the temperature range is maintained in the range of approximately one hundred and thirty to one hundred and thirty-five (130-135 F.) degrees. For this 2,300 gallon mixture a four-hour setting time is required to yield a product comprising approximately eighty-five percent sulfonic acid and fifteen (15%) percent extraneous material. In all, for the batch process of sulfonation and separation of the excess sulfonating agent from the sulfonic acid product there is required a total time of approximately seven to eight hours.

The sulfonic acid product has a typical analysis as follows: sulfonic acid, 87.7%; sulfuric acid, 8.5%; and, water, 3.8%. This product, even when neutralized may still contain considerable quantities of extraneous salt. A product that is nearly salt free can be made by using either sulfur trioxide or chlorosulfonic acid as the sulfonating or sulfating agent.

In a continuous process for the sulfonation of an alkyl aryl the alkyl aryl and sulfonating agent such as twentytwo (22%) percent fuming sulfuric acid, oleum, and intimately mixed to form a reaction solution or mixture. This mixture is allowedto digest at a temperature of approximately F. for a period of from eight to fifteen minutes. Then the mixture is mixed with water so as to form an emulsion comprising as the continuous phase excess sulfonating agent, i.e., with water and excess sulfonating agent as sulfuric acid, and as the discontinuous phase the sulfonic acid product. The viscosity of this emulsion is relatively low and by allowing the same to flow into a separation vessel the emulsion separates into the lighter sulfonic acid product and the heavier excess sulfonating agent. The time for the separation step is approximately ten minutes. The total time to sulfonate the alkyl benzene and then to separate the excess sulfonating agent from the sulfonic acid product is approximately 18-25 minutes. As contrasted with the batch process the continuous process is considerably shorter in the time requirement, i.e., 1825 minutes as contrasted with seven to eight hours.

In this invention we have developed continuous sulfonation and sulfation processes and an apparatus for carrying out the same wherein a reactant may be reacted with the sulfonating agent and/or a sulfating agent to produce a product. The gas employed in or generated in the reaction may be removed. More particularly, the reactant and the agent are substantially simultaneously completely contacted, mixed and reacted to form the There is no long digestion time for digesting the reactant and the agent to form the product. Actually, the agent and the reactant are so intimately mixed that upon mixing the same the. reaction takes place. This mixing time may take two or three seconds. Then, the mixture of the reactant to the agent is diluted with a large excess of a previously prepared product so as to substantially stop the reaction. This resulting mixture is then subjected to a pressure condition wherein the extraneous gas is removed therefrom. Then, the degassed resulting mixture comprises the product. There is no need to separate the product from excess sulfonating agent in the degassed resulting mixture because the amount of excess sulfonating agent is so small that it is not practical to separate the same. Furthermore, the contamination by this small amount of excess sulfonating agent is less than in previous process and systems wherein the excess sulfonating agent has been separated from the reactant. Therefore, if a neutralized product is desired it is possible to mix the acid product with an alkaline or caustic material to form the salt of the acid product. As is seen, the total reaction time to carry out this sulfonation and/ or sulfation process is very short, approximately four minutes or less. Also, the apparatus required to carry out this sulfonation and/or sulfation process is less than in the previous batch processes or the previous continuous processes.

Accordingly, it is an object of this invention to provide a sulfonating process, a sulfating process, and apparatus therefor which requires less time for the sulfonation and/ or sulfation of a reactant.

A further object is the provision of apparatus for sulfonation and/or sulfation wherein intimate contact is achieved between the sulfonating agent and/ or the sulfating agent and the reactant.

A further object is the provision of a sulfation process and a sulfonation process and apparatus therefor wherein a high quality product is realized as there is less degradation of the product by the sulfonating agent and/or the sulfating agent.

Another object is the provision of a sulfating process, a sulfonating process, and apparatus therefor, and which allows for the continuous removal of extraneous gas introduced to the reaction or generated in the reaction, and also to provide for the contacting of the reactants under various absolute pressures.

An additional object is the provision of a sulfonating process and a sulfating process and apparatus therefor wherein there is less sulfonating agent and/r sulfating agent in the final product as contaminants.

A still further object is the provision of a sulfating process and a sulfonation process wherein less costly and less complicated apparatus is required than in previous processes.

A still further important object of this invention is the provision of a sulfonation process and a sulfation process requiring lower cost equipment than previous processes.

These and other important objects and advantages of the invention will be more fully brought forth and presented in the following specification and claims.

Referring to the drawing, it is seen:

FIGURE 1 is a schematic outline of the apparatus required to carry out the sulfonation and sulfation procasses of this invention and also illustrates in schematic form the process.

FIGURE 2 is a fragmentary schematic outline of another variation in the process for reacting a sulfating agent and a reactant; and

FIGURE 3 is a fragmentary schematic outline of a variation in the process for reacting the product with a small amount of water prior to neutralizing the product.

This invention is for the processes of sulfonation and sulfation and includes the apparatus for carrying out these processes. Generally, in these processes a reactant capable of reacting with a sulfonating or sulfating agent is contacted with the agent in a mixing means. This mixing means is capable of substantially simultaneously completely contacting and mixing the reactant and the agent. The contacting and mixing is so complete that the reaction takes place in a very short period of time, i.e., almost upon the contacting and mixing of the reactant and the agent. However, degradation of the product is avoided because of the small excess of the agent with respect to the reactant and because of the low concentration of the agent in the mixture. Upon the basis of 100 mols of reactant there is normally employed 103 to 105 mols of the agent so as to provide an excess of approximately 3 to 5 mols of the agent. With this small excess of the agent, with the dilution of the sulfonating or sulfating agent with an excess of gas admitted to the reaction or generated in the reaction, or with a .low partial pressure of the agent degradation is maintained at a minimum. Furthermore, degradation is also largely eliminated because there is mixed in with these fresh reactants a large excess of the previously prepared and cooled product. This large excess on a volume basis is approximately at a minimum of fifteen parts of the product to one part of the combined volume of the reactant and the agent (15:1). The temperature of the recycled product is approximately 118 F. Therefore, due to its large excess, functions as a dilution factor and prevents the reaction mixture from staying at a relatively high temperature. In other words, due to the large excess of the previously prepared product the temperature of the new reaction mixture is brought down to one in the range of approximately 120 F. The new reaction mixture or diluted mixture is then degassed or the extraneous gas is removed. This is possible by spraying the diluted mixture into a tank whereby the pressure inside of the tank is such that the extraneous gas escapes and is removed. Some of the resulting degassed mixture is recycled through a heat exchanger and back into the mixing means so as to function as the coolant as previously explained. Some of the degassed mixture is then mixed with an alkaline material to form a neutralized product.

Restricting this at the present time to the reaction of chlorosulfonic acid with an alcohol and a non-ionic detergent, it is seen that the chlorosulfonic acid, a liquid, s mixed with the reactant to be sulfated. This mixmg is carried out in a mixing pump whereby the acid and the reactant are substantially simultaneously mixed and reacted within a very short period of time, i.e., less than about five seconds. There is employed a slight excess of the acid. More particularly, there is employed an approximately 2-5 mol percent excess of the acid with respect to the reactant so as to insure suflicient acid present to react with all the reactant. The temperature of the reactants are about room temperature. Upon the reactants being mixed the temperature rapidly rises to one in the range of 132138 F. The reaction mixture is in this temperature range for only a short period of time as it is diluted with a large excess of previously prepared product at a temperature of about 118 F. Also, degradation of the product is partially avoided because there is a very small excess of the acid. Upon the mixing of the reaction mixture with the previously prepared product there is formed a dilution mixture. When using chlorosulfonic acid to sulfate, large volumes of hydrogen chloride gas are liberated. Therefore it is necessary to remove this gas in order to produce a satisfactory product. This dilution mixture is sprayed into a column or tank or tower at a pressure of approximately fifteen to twenty-five inches Hg, absolute pressure, or conversely, at a vacuum of about five to fifteen inches Hg. At this pressure the hydrogen chloride gas or any extraneous gas in the dilution mixture is allowed to escape. The resulting degassed mixture is split into two parts. The first part is recirculated through a heat exchanger and introduced into the mixing means so as to act as a diluent, as previously explained, for the reaction mixture. Upon leaving the heat exchanger the temperature of this first part is approximately 117-118 F. The second part of the degassed mixture is introduced into a mixing means along with sodium hydroxide, or other neutralizer, to form a neutralized sulphate or product.

Referring now to the reaction between a reactant and sulfur trioxide it is seen that the sulfur trioxide may be employed as a sulfonating agent and as a sulfating agent. It is used to sulphate alcohols and unsaturated oils. As

a sulphonating agent it is used on alkyl benzene and unsaturates. The process for reacting the reactant with sulfur trioxide varies from that for reacting a reactant with chlorosulfonic acid. More particularly, sulfur trioxide, as is well known, is a gas at temperatures above F. The gaseous sulfur trioxide is mixed with an inert gas such as air, carbon dioxide ornitrogen to make a gaseous mixture. This gaseous mixture is then led into the mixing means along with the reactant. The ratio of the inert gas to the sulfur trioxide in this gaseous mixture is approximately 4 to 11 volumes of inert gas to one volume of the sulfur trioxide. In the mixing means the gaseous mixture and the reactant are substantially simultaneously completely contacted, mixed and reacted in a relatively short time. The temperature of the reactants are at approximately room temperature and rises to about 132 F. with the addition of nearly seventy (70%) percent of the sulfur trioxide. Thereafter the temperature of the reaction mixture is maintained in the range of 132-138 F. until completion of the addition of the sulfur trioxide. In this process there is employed from 25% excess sulfur trioxide over the theoretical requirement. The higher temperatures in the later stages of this mixing process is necessaryto keep the viscosity sufiiciently lo to permit the necessary violent agitation. While Within the same mixing means or of another mixing means the reaction mixture is diluted with a large excess of the previously prepared product at a temperature of about 117118 F. This dilution with a large excess of the previously prepared product at a lower temperature to form a dilution mixture decreases the temperature of the reaction mixture to a value of approximately 120-1Z2 F. The dilution mixture is then sprayed into a tower, so as to al ow extraneous gas to escape therefrom. The pressure in this tower or column may vary from approximately eleven inches of mercury absolute to about twenty-eight and one-half inches mercury absolute. In the reaction between the reactant and the sulfur trioxide there is employed approximately 25 mol percent excess of the sulfur trioxide. The sulfur trioxide is apparently 'dissolved Within the product so that in the degassing step the sulfur trioxide is not removed or does not escape. Therefore, in this degassing step the inert gas such as air, nitrogen or carbon dioxide escapes or is removed while the sulfur trioxide remains dissolved in the product. The product is then split into fractions. The first fraction is pumped through a heat exchanger whereby the temperature is lowered to a value of approximately 117- 118 F. and then introduced into the mixing pump to act as a diluent for the reaction mixture. The amount of first fraction recycled is at least fifteen volumes to one volume of the combined volume of the reactant. The residence time in the recycle loop including the degassing tank does not exceed three minutes maximum. The second fraction is then pumped to a mixing means wherein it is mixed with a neutralizing agent such as aqueous sodium hydroxide to form a neutralized product. However, before mixing with the neutralizing agent the second fraction may be mixed with a small amount of water, approximately two (2%) percent by weight so as to rleact with any anhydrides present and thereby break t em.

In the schematic diagram illustrating the apparatus proper and the combination of the apparatus, the separate units for carrying out sulfonation and sulfation are presented in FIGURES 1, 2 and 3. Referring to FIG- URE 1, this figure illustrates .sulfonation and sulfation with sulfur trioxide. It is seen that there is a source of sulfur trioxide 10. Generally, the sulfur trioxideis supplied in a liquid state and has been through a proportioning pump 11. It is introduced into a flash evaporator 12 whereby it is changed from a liquid state to a vapor state. As sulfur trioxide by itself is not employed for sulfonating because of its degrading qualities with .a reactant, there is mixed with the sulfur trioxide an inert gas such as air or nitrogen or carbon dioxide. Air 13 is fed into a proportioning pump 14. The gaseous sulfur'trioxide from the flash evaporator 12 and the air are fed into a mixer 15 whereby there is formed a gaseous mixture for reacting with the reactant 16. The gaseous mix ture of inert gas and sulfur trioxide and the reactant are fed into a mixingmeans 17. Leading into the intake of a centrifugal pump 17 are two concentric pipes 18 and 20. These concentric pipes terminate approximately oneeighth to one-fourth inch from the impeller blade in the pump. By terminating such a short distance from the impeller blade the gaseous mixture and the reactant are substantially simultaneously contacted and mixed. The gaseous mixture may be, for example, introduced through pipe 18 and the reactant may be fed by pipe 20 into the mixing pump 17. Following this pump, as previously stated, the gaseous mixture and the reactant are substantially simultaneously contacted and mixed into a reaction mixture. There is also introduced into the centrifugal pump, near the periphery of same, a cooled recirculation mixture 21. The volume of this cooled recirculation mixture is at least fifteen volumes to one volume of reaction mixture. The mixing of the cooled recirculation mixture and the reaction mixture in the mixing means 17 causes the formation of a diluted mixture 22. The temperature of the cooled recirculation mixture 21 is approximately 117-118" F., and the temperature of the diluted mixture is about 122123 F. The diluted mixture 22 is sprayed into a degassing column 23 by spray means 26. This degassing column 23 has a cylindrical Wall and a cone cap 25 therein. The cone cap, at its periphery, does not completely contact or is not in complete contact with the Wall 24. When the mixture 22 is sprayed into the column 23 extraneous gas escapes therefrom. The mixture flows down the walls of the column and collects in the bottom of the same to form a degassed reaction mixture 27. There is an exhaust means 28 and an aspirator or pressure unit 30 for adjusting the pressure in the column 23.

In combination with the degassing column 23 is a level control 31 comprising a control unit 33 and a float 32 inside of the column. This float varies with the level of the degassed reaction mixture in the column, and the control 33 connects with a control valve 34 whereby the flow of the product 37 is regulated. This will be more particularly described hereinafter. Connecting with the degassing column 23 is a pumping means 35 such as a centrifu gal pump or .a gear pump. The degassed reaction mixture flows to purnp35 and from there is split into two fractions, a recirculation mixture 36 and a product 37. There is a valve 38 in the recirculation mixture line which can be used for throttling the flow of the recirculation mixture. It is desirable to maintain the pressure on the degassed reaction mixture entering the recirculating pump 35. One Way of accomplishing this is to position the pump 35 a number of feet below the degassing column 23. For example, the pump 35 may be approximately three or more feet below the outlet of this column. The recirculating mixture 36 flows to a heat exchanger 40. As previously stated the temperature of this cooled recirculation mixture is approximately 117-118 F. The temperature of the recirculation mixture 36 entering the heat exchanger is approximately 122123 F. The total residence time in the recirculating loop should not exceed three minutes, and preferably much less.

The product 37 flows through valve 34 to centrifugal pump 41. Leading into this pump are two concentric pipes 42 and 43. These two pipes terminate about oneeighth to one-fourth inch from the impeller blade. The product 37, for example, can be fed into the pump .1 through pipe 42 and a neutralizing agent, such as aqueous sodium hydroxide 44, may be fed into the pump through pipe 43. By so introducing the product and the neutralizing agent into the pump they are substantially simultaneously contacted, mixed and reacted to form a neutralized product 45.

As previously stated the valve 34 is controlled by unit 31 so as to regulate the flow of the product 37. By regulating the flow of the product 37 it is possible to maintain. the level of the degassed reaction mixture in the column 23 at a constant low level. For example, if the level of the degassed mixture 37becomes too high then the valve 34 is opened so that more product can flow. Conversely, if the level of the mixture 37 becomes too low then the valve 34 is closed so as to decrease the quantity of the product 37 flowing therethrough. The same result can be accomplished with a sight glass and a manual control valve.

In FIGURE 2 there is illustrated a fragmentary portion of the apparatus for reacting the reactant 46 with chlorosulfonic acid 47. The reactant 46 may be introduced into centrifugal pump 17 through pipe 18 and the chlorosulfonic acid may be introduced into the pump through pipe 20. A cooled recirculation mixture 21 is also introduced intot he pump 17 near its periphery and there is expelled therefrom a diluted mixture 22. The rest of the system is the same as presented in FIGURE 1.

In FIGURE 3 there is presented a modification of the sulfonation apparatus of FIGURE 1. In this modification there is inserted between the valve 34 and the mixing means 41 a centrifugal pump or mixing means 48. Leading into this pump 48 through a pipe 51 is an aqueous medium such as water 52. Also, leading into this mixing means is pipe 50. The product 37 flows through valve 34 and through pipe 50 into the means 48. Water 52 flows through pipe 51 into this means 48. There results an aqueous product which flows through pipe 43 into mixing means 41. Aqueous sodium hydroxide solution 44 flows through pipe 42 into the mixing means 41 where it is mixed with the aqueous product to form a neutralized product. As previously stated the contacting of the product 37 with an aqueous medium, approximately two (2%) percent water by weight, breaks any anhydrides present in this product.

The size of the degassing column 23 depends uponthe plant capacity, but a column sufficient to handle two pounds of alkyl benzene per minute may be approximately four inches in diameter, about twelve inches in height from the level of the degassed reaction mixture which is maintained approximately four inches in depth.

Having presented a specific teaching of the sulfonation process, the sulfating process and the apparatus used for carrying out these processes, we will now present examples illustrating the same. It is to be understood that these examples are by way of illustration only and are not to be taken as limitations on the invention.

Example I A saturated fatty alcohol having the following composition is sulfated with chlorosulfonic acid:

Component: Percent by weight C12 65.7

C-16 Balance This alcohol is fed at a rate of nine pounds per minute through concentric pipes to the mixing pump 17 where it is mixed with 6.3 pounds per minute of chlorosulfonic acid. The reactants are also mixed with a large excess of recirculated acid from the degassing chamber. The resulting diluted reaction mixture, at a temperature of approximately 123 F., is sprayed into the degassing column 23 at an absolute pressure of approximately fifteen inches Hg. The recirculation rate of'the cooled reaction mixture, at a temperature of approximately 117 F., is at least twice the feed rate of the fresh reactants. The product 37 is neutralized with caustic soda to form a neutralized product. The resulting sulfate has the following analysis:

Example 11 An alkyl benzene having from ten to fifteen carbon atoms in the side chain was sulfonated with sulfur trioxide. The liquid sulfur trioxide was vaporized and the vapors mixed with air to make a mixture containing by volume, about eig'it (8%) percent sulfur trioxide. Five pounds per minute of the alkyl benzene were mixed with one and sixty-five hundredths pounds per minute of sulfur trioxide. The reactants were kept separated until they were introduced into a centrifugal pump wherein they were substantially simultaneously contacted and mixed into a reaction mixture. In turn the reaction mixture was mixed with a recycled cooled reaction mixture, flow rate of twenty-five gallons per minute, or in the ratio of about one part reaction mixture to about twentyfive parts recycled mixture (1:25), to form a dilution mixture. This dilution mixture flowed directly to a degassing chamber about twelve (12") inches in diameter and about eighteen (18") inches in height, and maintained at an absolute pressure of about ten (10") inches of mercury. From the bottom of the degassing chamber the acid was pumped by means of a positive displacement pump and through a heat exchanger where the temperature was adjusted to about F. The cooled reaction mixture then was recycled, to the mixing pump and a quantity of sulfonic acid equal to the rate of feed overflowed. The volume of the system was such that the average residence time was about one minute. Before being neutralized the acid was mixed with two (2%) percent by weight of water, and then mixed with an eighteen (18%) percent by weight sodium hydroxide solution to form a neutralized product having the following analysis.

Component: Percent by weight Active sulfonic acid 39.6 Free alkyl benzene oil 0.4 Sodium sulfate 1.9 Water Balance Having presented our invention it is to be realized that it may be employed with many different types of organic compounds such as the esters of organic acids, unsaturated and saturated esters, aliphatic aromatic compounds, alcohols both saturated and unsaturated, and the like.

We claim:

1. An apparatus for continuously reacting reactants, comprising, in combination, a centrifugal purr having an impeller blade, two concentric pipes leading into the centrifugal pump and terminating near the edge of th impeller blade, one of said concentric pipes being used to convey a first fluid reactant into the pump, the other one of said concentric pipes being used to convey a second fluid reactant into the pump, said impeller blade simultaneously contacting and mixing said fluids to form a r action mixture in the pump, a degassing chamber, means to vary the absolute pressure in the degassing chamber to a pressure less than atmospheric to permit extraneous gas to escape from the reaction mixture, a bafiie plate in said degassing chamber, a means to spray the reaction mixture over said baflle plate so as to have a large surface area per unit volume of the reaction mixture, conveying means interconnecting the pump and the degassing chamber to convey the reaction mixture from the pump to the means to spray the reaction mixture over said baflle plate, said degassing chamber removing extraneous gas from said reaction mixture to form a lower degassed reaction mixture layer and an upper gaseous layer, means in said degassing chamber responsive to the level of the degassed reaction mixture for controlling the level of the same, a recirculating pump, a heat exchanger, means interconnecting the degassing chamber, the recirculating pump, the heat exchanger and the centrifugal pump for conveying the degassed reaction mixture from the degassing chamber through the recirculating pump,

through the heat exchanger and to the centrifugal pump, a mixing means having a product outlet, means interconnecting the recirculating pump and the mixing means to convey the degassed reaction mixture from the forrrer to the latter, and a means connecting with the mixing means to introduce an aqueous alkaline material into the s mixing means. i

2. An apparatus comprising, in combination, a centrifugal pump for continuously and simultaneously contracting and mixing two reactants to form a reaction mixture, said centrifugal pump having three inlets and an outlet, one of said inlets being adapted to convey a gaseous reactant into said centrifugal pump, a second of said inlets being adapted to convey a fluid reactant into said centrifugal pump, a degassing chamber having an inlet and an upper gas outlet and a lower fluid outlet, means connecting said centrifugal pump outlet and said degassing chamber inlet to flow said reaction mixture from said centrifugal pump into said degassing chamber, means in said degassing chamber to separate said reaction mixture into an upper gaseous layer and a lower substantially degassed reaction mixture layer, a recirculating pump having an inlet and two outlets, a heat exchanger having an inlet and an outlet, means connecting said lower degassing chamber outlet with said recirculating pump inlet to flow said degassed reaction mixture from the former and into the latter, means connecting one of said recirculating pump outlets with said heat exchanger inlet to flow said degassed reaction mixture from the former to the latter to cool the degassed reaction mixture, means connecting said heat exchanger outlet with said third inlet of said centrifugal pump to flow said degassed reaction mixture from the former to the latter, said recirculating pump thereby pumping the degassed reaction mixture into said centrifugal pump to dilute and cool the reaction mixture in the latter, a mixing means having two inlets and a product outlet, means interconnecting said second recirculating pump outlet and one of said mixing means inlets to convey the degassed reaction mixture from the former to the latter, and a means connecting with said secondmix-v ing means inlet to introduce an aqueous material into said 'mixing means.

3. A reaction apparatus comprising, in combination, a centrifugal pump for continuously and simultaneously contacting and mixing reactants to form a reaction mixture, said centrifugal pump having three inlets and an outlet, two of said inlets being adapted to convey fluid reactants to said centrifugal pump, a degassing chamber having an inlet and an upper gas venting outlet and a lower reaction mixture outlet, means connecting the outlet of said centrifugal pump with the inlet of said degassing chamber to flow said reaction mixture from the former to the latter, said degassing chamber inlet being adapted to spray said reaction mixture over a baflle to form a lower fluid level and an upper gaseous level in said degassing chamber, said lower fluid level consisting of a substantially degassed reaction mixture, means in said degassing chamber responsive to the level of said degassed reaction mixture for controlling the level of' the same, a recirculating pump having an inlet and two outlets, means connecting the lower degassing chamber outlet and the recirculating pump inlet, a throttling valve to throttle the recirculating degassed reaction mixture, a heat exchanger having an inlet and an outlet, means connecting one of said recirculating pump outlets with said throttling valve, means connecting said throttling valve with the heat exchanger inlet to permit said degassed reaction mixture to be recirculated from said degassing chamber through said recirculating pump, through said throttling valve, and through said heat exchanger, means connecting the heat exchanger outlet and the third inlet of said centrifugal pump to permit said degassed reaction mixture to return to said centrifugal pump to dilute the reaction mixture therein, a mixing pump having two inlets and an outlet, means connecting said second recirculating pump outlet with one of said mixing pumpinlets to permit said degassed reaction mixture to flow from said recirculating pump and into said mixing pump, said second mixing pump inlet being adapted to convey an aqueous reactant into said mixing pump, said mixing pump outlet being adapteed to discharge said reaction mixture product.

4 An apparatus comprising, in combination, a centrifugal pump for continuously and simultaneously contacting and mixing reactants to form a reaction mixture, said centrifugal pump having three inlets and an outlet,

tWo of said inlets being adapted to carry reactable fluids into said centrifugal pump, a degassing chamber having an inlet and upper gas and lower fluid outlets, means to vary the absolute pressure in the degassing chamber, a baflle plate in said degassing chamber, a means to spray the reaction mixture over said baffle plate, conveying means interconnecting said centrifugal pump outlet and the degassing chamber inlet to convey said reaction mixture from the centrifugal pump to the means to spray the reaction mixture over said battle plate, said degassing chamber removing extraneous gas from said reaction mixture to form an upper gaseous layer and a lower degassed reaction mixture layer, an interface control in said degassing chamber responsive to the level of the degassed reaction mixture for controlling the level of the same, a recirculating pump, a heat exchanger, means interconnecting said lower fluid outlet of the degassing chamber, the recirculating pump, the heat exchanger and said third centrifugal pump inlet for conveying the degassed reaction mixture from the degassing chamber through the recirculating pump, through the heat exchanger and into said third centrifugal pump inlet, the total residence time from said centrifugal pump outlet to said third centrifugal pump inlet being less than about three minutes, a control valve and a mixing means having two inlets and a product outlet, means interconnecting the recirculating pump, the control valve and oneof said mixing means inlets to convey the degassed reaction mixture from the recirculating pump through the control valve and to the mixing means, means connecting with said second mixing means inlet to introduce an alkaline material into said mixing means, and means connecting said interface control and said control valve to regulate the flow of said degassed reaction mixture.

5. An apparatus for continuously reacting reactants, comprising, in combination, a centrifugal pump having an impeller blade, two concentric pipes leading into the centrifugal pump and terminating near the edge of the impeller blade, one of said concentric pipes being used to convey a first fluid into the pump, the other one of said concentric pipes being used to convey a second fluid into the pump, said impeller blade simultaneously contracting and mixing said fluids to form a reaction mixture in the pump, a degassing chamber,

means to vary the absolute pressure in the degassing chamber to a pressure as low as fifteen inches of mercury absolute pressure, a baflle plate in said degassing chamber, a means to spray the reaction mixture over said baffle plate so as to have a large surface area per unit volume of the reaction mixture, conveying means interconnecting the pump and the degassing chamber to convey the reaction mixture from the pump to the means to spray the reaction mixture over said baffle plate, said degassing chamber removing extraneous 'gas from said reaction mixture to form an upper gaseous layer and a lower degassed reaction mixture layer, means in said degassing chamber responsive to the level of the lower degassed reaction mixture layer for controlling the level of the same, a recirculating pump, a heat exchanger, means interconnecting the degassing chamber, the recirculating pump and the heat exchanger for conveying the degassed reaction mixture from the degassing chamber through the recirculating pump and to the heat exchanger, means interconnecting the heat exchanger and the centrifugal pump to convey the degassed reaction mixture from the former to the latter to act as a coolant and diluent in the latter, said recirculating pump having the capacity to pump at least fifteen volumes of the degassed reaction mixture per one volume of the combined volumes of the first and the second fluids entering the centrifugal pump, a mixing means having a product outlet, means interconnecting the recirculating pump and the mixing means to convey the degassed reaction mixture from the former to the latter, and a means connecting with the mixing means to introduce an alkaline material into said mixing means.

References Cited in the file of this patent UNITED STATES PATENTS 

1.AN APPARATUS FOR CONTINUOUSLY REACTING REACTANTS, COMPRISING, IN COMBINATION, A CENTRIFUGAL PUMP HAVING AN IMPELLER BLADE, TWO CONCENTRIC PIPES LEADING INTO THE CENTRIFUGAL PUMP AND TERMINATING NEAR THE EDGE OF THE IMPELLER BLADE, ONE OF SAID CONCENTRIC PIPES BEING USED TO CONVEY A FIRST FLUID REACTANT INTO THE PUMP, THE OTHER ONE OF SAID CONCENTRIC PIPES BEING USED TO CONVEY A SECOND FLUID REACTANT INTO THE PUMP, SAID IMPELLER BLADE SIMULTANEOUSLSY CONTACTING AND MIXING SAID FLUID TO FORM A REACTION MIXTURE IN THE PUMP, A DEGASSING CHAMBER TO VARY THE ABSOLUTE PRESSURE IN THE DEGASSING CHAMBER TO A PRESSURE LESS THAN ATMOSPHRIC TO PERMIT EXTRANEOUS GAS TO ESCAPE FROM THE REACTION MIXTURE, A BAFFLE PLATE IN SAID DEGASSING CHAMBER, A MEANS TO SPARY THE REACTION MIXTURE OVER SAID BAFFLE PLATE SO AS TO HAVE A LARGE SURFACE AREA PER UNIT VOLUME OF THE REACTION MIXTURE, CONVEYING MEANS INTERCONNECTING THE KPUMP AND THE DEGASSING CHAMBER TO CONVEY THE REACTION MIXTURE FROM THE PUMP TO THE MEANS TO SPRAY THE REACTION MIXTURE OVER 